Association of somatosensory evoked potentials with cervical spinal cord atrophy and disability progression in multiple sclerosis.

OBJECTIVES

Somatosensory evoked potentials (SEP) reflect functional integrity of sensory pathways and may predict disability progression in multiple sclerosis (MS). Cervical spinal cord atrophy is thought to reflect neurodegenerative processes and may contribute to disability in MS. This study aimed to investigate the association between SEP abnormalities, cervical spinal cord atrophy, and disability progression in MS.

METHODS

In this retrospective cohort study, MS patients who underwent SEP examination and had at least two cervical spinal MRI scans acquired more than one year apart were included. Cervical spinal cord cross-sectional areas (C2-3, C3-4) were automatically quantified using a validated deep learning segmentation model. SEP and visual evoked potentials (VEPs) were dichotomized as normal or pathological based on institutional normative values. Disability progression was assessed by time to Expanded Disability Status Scale (EDSS) scores of 3 and 6 using Kaplan-Meier survival analysis and Cox proportional hazards models.

RESULTS

A total of 47 patients were included. SEP abnormalities were observed in 46.8% of patients. Pathological SEP was associated with higher annual cervical spinal cord atrophy rates and a significantly shorter time to EDSS 3, but not EDSS 6. Pathological SEP was associated with earlier attainment of EDSS 3 (HR 3.4).

DISCUSSION: SEP abnormalities are associated with increased cervical spinal cord atrophy and early disability progression in MS, supporting SEP as an electrophysiological biomarker of spinal cord involvement.